You can easily unlink backup files saved in your Dropbox folder so that the folders/files will be save in your PC instead of Dropbox by following below mentioned steps:
If you are not getting Manage Backup option while following above steps then click on Dropbox icon (mentioned on bottom right side) > Preferences > Backup > Manage Backup
2. Untick the folders which you wants to remove from Dropbox.
3. Always click on Keep content in folders on this PC, then stop backup. After that you data or files will be save in your PC only.